<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Feed_Reader
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Feed.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @see Zend_Feed_Reader_Extension_FeedAbstract
 */
require_once 'Zend/Feed/Reader/Extension/FeedAbstract.php';

require_once 'Zend/Date.php';

/**
 * @category   Zend
 * @package    Zend_Feed_Reader
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Feed_Reader_Extension_Syndication_Feed extends Zend_Feed_Reader_Extension_FeedAbstract {
	/**
	 * Get update period
	 * @return string
	 */
	public function getUpdatePeriod() {
		$name = 'updatePeriod';
		$period = $this->_getData ( $name );
		
		if ($period === null) {
			$this->_data [$name] = 'daily';
			return 'daily'; //Default specified by spec
		}
		
		switch ($period) {
			case 'hourly' :
			case 'daily' :
			case 'weekly' :
			case 'yearly' :
				return $period;
			default :
				throw new Zend_Feed_Exception ( "Feed specified invalid update period: '$period'." . " Must be one of hourly, daily, weekly or yearly" );
		}
	}
	
	/**
	 * Get update frequency
	 * @return int
	 */
	public function getUpdateFrequency() {
		$name = 'updateFrequency';
		$freq = $this->_getData ( $name, 'number' );
		
		if (! $freq || $freq < 1) {
			$this->_data [$name] = 1;
			return 1;
		}
		
		return $freq;
	}
	
	/**
	 * Get update frequency as ticks
	 * @return int
	 */
	public function getUpdateFrequencyAsTicks() {
		$name = 'updateFrequency';
		$freq = $this->_getData ( $name, 'number' );
		
		if (! $freq || $freq < 1) {
			$this->_data [$name] = 1;
			$freq = 1;
		}
		
		$period = $this->getUpdatePeriod ();
		$ticks = 1;
		
		switch ($period) {
			//intentional fall through
			case 'yearly' :
				$ticks *= 52; //TODO: fix generalisation, how?
			case 'weekly' :
				$ticks *= 7;
			case 'daily' :
				$ticks *= 24;
			case 'hourly' :
				$ticks *= 3600;
				break;
			default : //Never arrive here, exception thrown in getPeriod()
				break;
		}
		
		return $ticks / $freq;
	}
	
	/**
	 * Get update base
	 *
	 * @return Zend_Date|null
	 */
	public function getUpdateBase() {
		$updateBase = $this->_getData ( 'updateBase' );
		$date = null;
		if ($updateBase) {
			$date = new Zend_Date ();
			$date->set ( $updateBase, Zend_Date::W3C );
		}
		return $date;
	}
	
	/**
	 * Get the entry data specified by name
	 *
	 * @param string $name
	 * @param string $type
	 * @return mixed|null
	 */
	private function _getData($name, $type = 'string') {
		if (array_key_exists ( $name, $this->_data )) {
			return $this->_data [$name];
		}
		
		$data = $this->_xpath->evaluate ( $type . '(' . $this->getXpathPrefix () . '/syn10:' . $name . ')' );
		
		if (! $data) {
			$data = null;
		}
		
		$this->_data [$name] = $data;
		
		return $data;
	}
	
	/**
	 * Register Syndication namespaces
	 *
	 * @return void
	 */
	protected function _registerNamespaces() {
		$this->_xpath->registerNamespace ( 'syn10', 'http://purl.org/rss/1.0/modules/syndication/' );
	}
}
